Process fob making shrapnel-shells



' w. 0. RICE PROCESS FOR MAKING SHRAPNEL SHELLS.

Patented May 13, 1919.

UNITED STATES PATENT orricn.

1). nice, or commnnr, OHIO.

rnocEss r013. minus SHRAPNEL-SHELLS.

To all whom it may concern:

Be it known that I, WILLIAM D. RICE, a

A citizen of the United States, residing at Conneaut, in the county ofAshtabula and 7 ing Shrapnel-Shells, of

State of Ohio, have invented certain new and useful Improvements inProcesses for Makwhich the following is a specification.

My invention relates to an improvement in the process for makingshrapnel shells.

The object is to provide and construct a shell of a frangible nature,which will be so constructed that it will burst upon explosion intoinnumerable fragments, due to a difference in the strength of its wallsat certain 7 areas.

It therefore consists in a shell of the character specified, and in amethod of construction, in which there are a series of operations, towit:the'casting of a hollow shell of steel, which might be termedcommercial cast steel, with walls. of unequal thickness;

7 a re-heating of the shell; compressing the a shell; carburizing theshell; and finally machining and reducing to a perfect surface,whereby-parts are removed, thereby leaving ashell made up of hard andsoft areas.

In the accompanying drawings Figure 1 is a longitudinal sectional vlewbefore machining;

Fig. 2 is a similar view after machining; Fig. 3 is a transverse sectionthrough raised areas which may be square, diamond- Fig. 4 is atransverse section through l ig. 5 is a view showing the-application ofthe invention to both surfaces of the shell.

A, is a cast shell, which may have grooves cast in the internal orexternal surface, or both, as shown in Figs. 1 and 5, thus leavingshape, or any other form.

After casting, the shell is placed in an oven or-retort and heated to atemperature of approximately 1400 F. for the purpose of giving ituniformity of hardness.

The shell is then removed from the oven or retort, after having reachedapproximately the degree of temperature specified,

Specification of Letters Patent.

Patented May 13, 1919.

Application filed September 22, 1917. Serial No. 192,703.

which is the making of the grain in the thinner places of the shell moredense than in the thicker areas.

It is a well-known fact that when steel cools, the thicker portionshave'a tendency to pull away from the thinner portions, causing a slightdeterioration of the grain in the thinner places, which is known amongthose engaged in casting steel as shrinkage cracks which have a tendencyto weaken the areas where this condition exists, and nothing butre-melting could ever give these places the same consistency as thethicker places of the casting.

After the shell is thus cast, re-heated and compressed, it is carburizedin any approved manner, and with any well-known material, as forinstance by the use of granulated bone such as ground bone or any othercarbonaceous material. Either or both surfaces may be carburized, but itis my intention to carburize only the grooved surface whether that bethe interior or exterior or both sur-' faces of the shell.

An .approved method of carburizing would be to place the shell incast-iron boxes, lead crucibles, or whatever containers the manufacturerdeems desirable, in which the shell is packed loosely with granulatedbone such as ground bone or other carbonaceous material. T o harden theshell, it is subjected to a qu'enchin process, and the part of the shellthat has I een combined with the carbon will harden to a greater degreethan the raised portions, and the quenching process should not becarried sufficiently far to make the shell too brittle for use. Eitherwater, oil, or aircan be used for quenching. This is the last process towhich the shell is subjected.

There is a final machining which takes place which'results in removingthe thickened portions left by the grooves in casting, thus making theshell of uniform thickness instead of irregular thickness as at thebeginning; and it is due to this final machining, which removesor'reduces these thickened areas, and, consequently, the carburized orhardened surface of these areas, that the completed shell is made up ofhard and soft areas, which results in its fracture, upon an explosiontaking place, ina maximum number of parts. v

By means of this improved process, the completed shell will have a hard,brittle and friable surface, and the harder and more friable placeswillbe. in the lines between the original raised areas, which, in theend,have been machined off. As previously stated, this is due to the factthatlthe thinnest part of the shell will have the closestv grain, thusbeing more susceptibleto carburizing, and hence will be more brittlethan the parts under the raised portions which have been re-h'eated andmachined'ofi', and the result will be that the shell will breakin-practically asmany pieces as there were originally thickened areas.

' The temperature. of annealing of steel castings depends entirely uponthe chemical composition. For instance, for an ordinary steel casting ofabout .30 carbon, With'.60 manganese, .20 silicon, .05 phosphorus, and

' .105 sulfur, the 'annealingtemperature would ard for theiordinarysteel casting.

be approximately 1575 to 1600. This would be lowered for a higher carbonand raised fora lower carloeon,v It would likewise be raised for. alower manganese and lowered for which I have given areapproximately-.stand .1 do not desire a)v be limited to an -paticularmethod of casting, 're -heating,,c omthickness,

quired degree, subjecting it to compression,-

a higher manganese, but the. figures carburizing the irregular surfaceto a suitable depth, and finally machining or otherwise removing theirregular surface to give -it' uniformity, thereby removingthethickenedareas and the portions thereof which are hardened, andleaving. the, intervening hardened areas. r

'- .2. An improved method of constructing shells, which consists incasting a shell of 4 steel with a body of varying or irregularthickness, re-heati ng the shell to the required. degree, subjecting ittocompression,

case hardening the irregular surface to a suitable depth, then machiningor otherwise 50 removing vthe. irregular surface to give it uniform ty,then re-heating and finally quenching. w

- In testimony, whereof I aflix my signature.

- WILLIAM- D. RICE.

